如何将WAV文件切成10ms数据

问题描述

我试图将从wav中检索到的数据划分为10ms的段，以进行动态时间扭曲.

I am trying to divide the data I retrieve from a wav into 10ms segments for dynamic time warping.

    import wave
    import contextlib

    data = np.zeros((1, 7000))
    rate, wav_data = wavfile.read(file_path)
    with contextlib.closing(wave.open(file_path, 'r')) as f:
        frames = f.getnframes()
        rate = f.getframerate()
        duration = frames / float(rate)

是否有任何现有的库可以做到这一点

Is there any existing library that do that

谢谢

推荐答案

如果您对数据进行后期处理感兴趣，则可以将其作为numpy数据使用.

If you're interested in post-processing the data, you'll probably be working with it as numpy data.

>>> import wave
>>> import numpy as np
>>> f = wave.open('911.wav', 'r')
>>> data = f.readframes(f.getnframes())
>>> data[:10]  # just to show it is a string of bytes
'"5AMj\x88\x97\xa6\xc0\xc9'
>>> numeric_data = np.fromstring(data, dtype=np.uint8)
>>> numeric_data
array([ 34,  53,  65, ..., 128, 128, 128], dtype=uint8)
>>> 10e-3*f.getframerate()  # how many frames per 10ms?
110.25

这不是整数，因此除非您要对数据进行插值，否则需要将数据填充零以获取110帧长的样本(在此帧速下大约为10ms).

That's not an integer number, so unless you're going to interpolate your data, you'll need to pad your data with zeros to get nice 110 frames long samples (which are about 10ms at this framerate).

>>> numeric_data.shape, f.getnframes()  # there are just as many samples in the numpy array as there were frames
((186816,), 186816)
>>> padding_length = 110 - numeric_data.shape[0]%110 
>>> padded = np.hstack((numeric_data, np.zeros(padding_length)))
>>> segments = padded.reshape(-1, 110)
>>> segments
array([[  34.,   53.,   65., ...,  216.,  222.,  228.],
       [ 230.,  227.,  224., ...,   72.,   61.,   45.],
       [  34.,   33.,   32., ...,  147.,  158.,  176.],
       ..., 
       [ 128.,  128.,  128., ...,  128.,  128.,  128.],
       [ 127.,  128.,  128., ...,  128.,  129.,  129.],
       [ 129.,  129.,  128., ...,    0.,    0.,    0.]])
>>> segments.shape
(1699, 110)

因此，现在segments数组的每一行都长约10ms.

So now, every row of the segments array is about 10ms long.

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